[1] Univ Gothenburg, Sahlgrenska Acad, Dept Clin Neurosci, Gothenburg, Sweden
[2] Sahlgrens Univ Hosp, Dept Neurol, Reg Vastra Gotaland, Gothenburg, Sweden
[3] Karolinska Inst, Dept Clin Neurosci, Stockholm, Sweden
[4] Karolinska Univ Hosp, Dept Neuroradiol, Stockholm, Sweden